Improvement in scaffolds



PATENT @Priori ALONZO S. DRISKO, OF BOSTON, MASSACHUSETTS.

EMPROVENIENT IN SCAFFLDS.,

Specification forming part of Letters Patent No. 150,065, dated April2l, 1874; application filed March 5, 1874.

l To all whom it may concern:

-Boston, in the count-y of Suil'olk and State of Massachusetts, haveinvented certain Improvements inv Scaffolding or Staging for the use ofmasons, carpenters, and other mechanics, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, making part of this specification, in which-Figure l is a perspective view of my iinproved frame-work for supportingone end of the staging. Fig. 2 is a transverse vertical section throughthe center of the same.

The ordinary staging or scaffolding employed by masons, carpenters, andother mechanics in building walls, lat-hing, plastering, painting, Ste.,consists of a platform composed of plank placed across two or morehorses, another platform, also consisting of horses and plank, erectedon the lower platform, being required to enable the mechanic to changehis position to more conveniently obtain access to the work as itprogresses from time to time, a staging so constructed occupyingconsiderable time, and involving much labor in its erection, besideswhich all the tools and materials on one platform have to be removed toanother platform every time a change in the height of the stagingbecomes necessary. To overcome the above-mentioned objections is thepurpose of my invention, which consists in a traine-work, composed of apair of standards connected by a horizontal transverse frame, upon whichrest the ends of the plank which form the platform, upon which thematerials and tools are deposited, and upon which the workmen standwhile at work, the standards being provided with a series of notches,and the transverse frame with pawls, which engage therein, by whichconstruction it is simply necessary to trip the pawls, by a cord orotherwise, to enable the workmen to readily lower the platform, a lever,in connection with an adjustable fulcrum, being employed for raising it,the notches being placed so near together that the platform may beconyeniently adj usted into various positions, differing very slightlyin height from each other, the

materials and implements upon the platform remaining uninoved thereonduring its adjustment.

To enable others skilled in the art to understand and use my invention,I will proceed to describe the manner in which I have carried it'out.

In the said drawings, A A represent two standards, each rising from thecenter of a base or foot piece, B, to which it is securely stayed bybraces a a. The outer surface of each standard is provided with a seriesot' notches, b I), separated about two inches from each other, and for apurpose to be presently explained. The two opposite side surfaces ofcach standard are provided with vertical grooves c c, for the receptionof the outer bent ends d (l of plates or straps O, two of which aresecured to each of the opposite sides of each end of a frame, D,composed of two horizontal cross-beams, c f, connected by uprights E,the ends of the plank 4, for forming the platform, being intended torest on the upper beam, e, by which construction the frame is free toslide up'and down within the stainlards, and the frame and its platesserve to prevent the standards from spreading apart. lVithin eachupright E, at t', is pivoted a lever, G, of the forni seen in Fig. 1,the outer portion of the lever being bifurcated, and extending outsideof and inclosing the upright portion of the frame D and the standard A,the outer ends of the bifurcations being united by a cross -piece, k,made separately from or 'in one and the same piece therewith, andresting in one of the notches b, the bifurcated lever, with itscross-piece k, serving as a pawl to prevent the frame D from slippingafter being adjusted in position. The inner orlstraight portion of eachlever has secured to its inner end a rope or cord, l, by pulling down onwhich the two pawls or cross-pieces k are brought rmly down on theirnotches, and bear forcibly in a lateral direction against their inclinedsurfaces, whereby increased security against the slipping down oftheframe is insured, and an additional bond formed between the standardsand the frame. The cord lis intended to be caught around a pin or cleat,m, to prevent the pawls from being accidentally thrown up and theconsequent dropping ofthe frame. II is a cross-bar, extendinghorizontally from one standard to another, enlargements or projections5, on the ends of the cross-bar, resting on the sides of the standards,each end of the cross-bar being provided with a hook, u, which fits intoone of the notches b, and extends around to the opposite side of thestandard, by which the cross-bar is securely held when suspended fromthe standards at any desired height, the object of the cross-bar beingto provide a fulcrum for a lever, I, whose inner end p is to be insertedunder the lower beam f when it is desired to raise the frame to elevatethe platform, so as to enable the workman to have access to the work asit progresses, the pressure of the lever down on the cross-bar servingto increase instead of reduce the stability of the frame-work andplatform while the latter is being raised. After being raised to therequired height, the pawls drop'into their notches, and the slidingframe and platform are thereby held securely in place. When the platformis to be lowered, the frame D, at each end, is allowed to graduallyslide down on its standards, by drawing up the inner ends of the leversby a cord, s, fastened thereto, and passing up over a pulley, t, hung inor to the lower side of the upper beanie, it being necessary rst toloosen the cord l, care being had to trip the levers only sufficientlyto allow of the pawls successively engaging with the notches beneath,and the platform or staging, if heavily loaded, being eased in itsdescent by a counter resistance exerted by the lever I, with its innerend placed under the lower beam j', and having its fulcrum on thecross-bar H. Instead of the standards being provided with grooves c c,as shown, the latter may be dispensed with, and the standards beprovided with projecting rails, as guides for the frame D to slide on,in which ease the latter would be provided with grooves, and the platesC would be dispensed with; but I prefer the construction firstdescribed.

From the foregoing, it will be seen that a staging constructed inaccordance with my invention may be easily and quickly set up, andadjusted to various heights without the necessity of removing the loadthereon; besides which it combines safety with strength and durability,andthe parts may be stowed away compactly when not in use, and can betransported from place to place with great facility.

Vhat I claim as my invention, and desire to secure by Letters Patent asan improvement in scaffolding, is*- 1. The pawl-clasp G, pivoted in thesliding frame D, in combination with the notched standards A A7 as andfor the purpose set forth.

2. The cross-bar H, in combina-tion with the links n, lever I, andnotched standards A A, substantially as described.

Vitness iny hand this 26th day of Febrn ary, A. D. IS7/l..

ALONZO S. DRISKO.

In presence ofl?. E. Tnscnnirzionnn, \V. J. CAMBRIDGE.

